cover
Contact Name
-
Contact Email
jag.ft@ugm.ac.id
Phone
+62274-513668
Journal Mail Official
jag.ft@ugm.ac.id
Editorial Address
Geological Engineering Departement Universitas Gadjah Mada Jl. Grafika No. 2 Kampus UGM Yogyakarta 55281 Phone +62-274-513668 Fax +62-274-546039
Location
Kab. sleman,
Daerah istimewa yogyakarta
INDONESIA
Journal of Applied Geology
ISSN : 25022822     EISSN : 25022822     DOI : https://doi.org/10.22146
Journal of Applied Geology – JAG focuses on the applied geology and geosciences with its key objective particularly emphasis on application of basic geological knowledge for addressing environmental, engineering, and geo-hazards problems. The subject covers variety of topics including geodynamics, sedimentology and stratigraphy, volcanology, engineering geology, environmental geology, hydrogeology, geo-hazard and mitigation, mineral resources, energy resources, medical geology, geo-archaeology, as well as applied geophysics and geodesy.
Articles 180 Documents
Landslide Susceptibility Mapping of Menoreh Mountain Using Logistic Regression Nadia Sekarlangit; Teuku Faisal Fathani; Wahyu Wilopo
Journal of Applied Geology Vol 7, No 1 (2022)
Publisher : Geological Engineering Department Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jag.72067

Abstract

Menoreh mountain is one of the priority areas developed for tourism and to support sustainable development, it must pay attention to disaster aspects, one of which is landslides. The map published by Center for Volcanology and Geological Hazard Mitigation of Indonesia (PVMBG) has a regional scale, so it is necessary to have a more detailed landslide susceptibility map in the Menoreh Mountains. Identification and evaluation of the landslide conditioning factor were done using logistic regression so that the zonation of the probability of landslide susceptibility can be made. The data was used from field observation conducted at 372 locations including 129 locations where landslides occurred and from a local disaster management agency (BPBD) of 200 landslide locations. Significant landslide conditioning factors include slope, lithology, distance to lineaments, distance to river, and distance to road. The research area is divided into three susceptibility zones classified into low landslide susceptibility zone (0-0.33) covering 39.82%, moderate landslide susceptibility zone (0.34-0.66) covering 25.86%, and high landslide susceptibility zone (0.67-1.00) covering 34.31% of the whole area. Analysis using the logistic regression method has a model prediction accuracy rate of 90.5%, which means that it can predict landslide occurrence in the Menoreh Mountains accurately.
Geochemistry of shield stage basalts from Baluran volcano, East Java, Sunda arc Esti Handini; Toshiaki Hasenaka; Nicholas D Barber; Tomoyuki Shibata; Yasushi Mori
Journal of Applied Geology Vol 7, No 2 (2022)
Publisher : Geological Engineering Department Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jag.73697

Abstract

We report petrography and geochemistry of basaltic lava flows from the shield stage of Baluran, a Quaternary volcanic center in the rear of East Java, Sunda Arc, Indonesia. These basalts contain abundant plagioclase, clinopyroxene, olivine, and minor magnetite. Geochemically, they resemble other medium-K calc alkaline basalts from eastern Java’s volcanoes, but they are less enriched in light ion lithophile elements (LILE) and Pb. The predicted primary basalt of Baluran lavas can be sourced to a more primitive primary melt composition which may also generate medium-K calc-alkaline magmas in the region. The fractionation trajectory of these primary magmas shows the importance of plagioclase, clinopyroxene, olivine, and magnetite phase removal from the melt. Regardless of the diverse composition of the derivatives, the calculated primary basalts from the eastern Java are all in the field of nepheline-normative. This finding suggests variably small degree of melting of clinopyroxene-rich mantle source is at play in the generation of these magmas. Our result further suggests that the clinopyroxene source rock is possibly present as veins in peridotite mantle which have experienced metasomatism by addition of slab-derived fluids at differing proportion.
Engineering Geology and Slope Stability of West Pit Coal Mine of PT. Tawabu Mineral Resource, East Kalimantan, Indonesia Rama Tri Saksono; I Gde Budi Indrawan; Wahyu Wilopo
Journal of Applied Geology Vol 7, No 2 (2022)
Publisher : Geological Engineering Department Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jag.76532

Abstract

The research area was located in the west pit of the open pit coal mine of PT. Tawabu Mineral Resource (TMR) which is located in Bengalon District, East Kutai Regency, East Kalimantan Province, Indonesia. The research was driven by several landslides that occurred in the research area, but the engineering geological conditions and stability of the remaining slopes have not been evaluated. The objectives of this study were to better understand the engineering geological conditions and stability of the research area. The engineering geological conditions (i.e., geomorphology, rock and soil, geological structure, and groundwater conditions) were evaluated by photogrametric analyses, field observations, and analyses of borehole logs and laboratory test results. The slope stability analyses were firstly carried out by conducting back stability analyses of failed slope on the northern lowwall slope segment. The shear strength parameters obtained from the back analyses were then used for forward stability analyses of the remaining 10 lowwall and highwall slopes. The slope stability analyses involved deterministic and probabilistic analyses, under static and dynamic using the limit equilibrium method (LEM).  The results showed that the research area and the surrounding consisted of two geomorphological units, namely the alluvial plain and structural hills. Rocks in the study area consisted of claystone, sandstone, and coal with a general layer strike direction of N59°E – N63°E with a dip of 19°-26°. These rocks were grouped into two lithological units, namely the alternating of claystone and sandstone unit and alternating of sandstone and claystone unit. The geological structures were identified on the highwall, from west to east namely major sinistral shear fault with a relative direction of NNE-SSW, two minor sinistral shear faults with a relative direction of NE-SW, and a major dextral shear fault with a relative direction of NW-SE. These geological structures were interpreted as being formed by the folding process. The groundwater level was estimated at a level of -45 m to 20 m. The slope stability analyses showed that only the East HW-4 slope, which was located on the east highwall, was unstable. It is recommended to optimize the slope by either lowering the groundwater elevation by 4 m from the actual level or by reducing the angle the overall slope to 31°.
Facies Analysis and Reservoir Characterization Using Petrophysical Methods in the Interest Zone in the 'FAN' Field, Kutai Basin, East Kalimantan Isfan Fajar Fathur Rahman; Wahju Krisna Hidajat; Reddy Setyawan; Yunita Meilany; Dhimas Aditya Nugraha
Journal of Applied Geology Vol 7, No 2 (2022)
Publisher : Geological Engineering Department Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jag.73457

Abstract

One of the most prospective oil and gas producing basins in Indonesia is Kutai Basin which is located in East Borneo. In Kutai Basin there is a natural resource potential in the form of gas which is quite abundant. This is due to the richness of the source rock aspect in the Kutai Basin which is dominated by coal. Besides coal, in the Kutai Basin there is also claystone with rich organic matter (organic shale) that has an important role as a prospective source rock. Therefore, a final project research was conducted in the Kutai Basin, East Kalimantan. The purpose of the research is to identifying the type and content of subsurface lithology and fluids, calculating petrophysical parameters, and making the facies distribution map at the research site in potential and prospective zone to produce hydrocarbons which is called the zones of interest. The research is focused on reservoir rocks at the research site because the hydrocarbons accumulated in the reservoir rocks itself. By focusing research on reservoir rocks, it will be able to describe the modelling and calculation results of petrophysical parameters using several analytical methods such as qualitative and quantitative analysis methods, electrofacies and parasequence analysis methods, stratigraphic correlation analysis methods, facies analysis methods and depositional environments, and facies map analysis methods. In addition, by focusing research on reservoir rocks, it can develop and increase the level of optimization of exploration and exploitation of drilling wells. Based on the analysis data, the research location is included in the transitional depositional environment, delta in particular with distributary channels and mouth bars facies and also it can be identified some lithology such as sandstone, claystone, coal, limestone, and organic claystone and there are fluids with gas and water types.
Susceptibility Zoning of Soil Movement in Tawangmangu District, Karanganyar Regency with Bivariate Statistic Method - Weight of Evidence Dwika Rizki Wirawan; Agung Setianto; Esti Handini
Journal of Applied Geology Vol 7, No 2 (2022)
Publisher : Geological Engineering Department Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jag.78754

Abstract

Tawangmangu district which is located in Karanganyar Regency, Central Java is a crowded area which is susceptible to disaster. Therefore, susceptibility zoning analysis is needed to support the planning and development of the area. The method used is bivariate statistics - weight of evidence which has never been implemented in its location. There are two types of data, data of potential and soil movement case (divided into train data as 61 points and test data as 40 points); and parameter data of soil movement causes. Parameter data of soil movement is processed to be a WoE (Weight of Evidence) parameter map through the use of train data to know the weight. Later on, it will be validated based on the AUC value. If it’s > 0,60, then the process will proceed. Parameter which has AUC value > 0,60 is type of lithology, slope, hill, elevation, slope direction, distance from the fault, and index of vegetation density. All of those parameters are attached and being final validated by test data. Further, the zonation consists of four; zone of very low soil movement susceptibility, low, medium, and high. The area of the very low soil movement susceptibility zone is 19,68%. Zone of low susceptibility is mostly 24,57%. Zone of medium susceptibility is 25,88%. Meanwhile, the zone of high susceptibility is 29,86%. The result of final validation shows that AUC value from the zoning model made belongs to a good category, which is 0,757.
Petrophysical Study and Rock Type Determination of Siliciclastic Reservoir: Case Study Sand of Bekasap Formation, AF Field, Central Sumatra Basin, Indonesia Dwi Charisah Andriyani; Sarju Winardi; Sugeng Sapto Surjono
Journal of Applied Geology Vol 7, No 2 (2022)
Publisher : Geological Engineering Department Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jag.83471

Abstract

An integrated subsurface study has been performed for a large and mature field at the Bekasap Formation in Central Sumatra Basin. The Bekasap Formation sand represents an undeveloped reservoir because of its heterogeneity. There are five sand reservoirs (BK1, BK2, BK3, BK4, and BK5) from Bekasap Formation, which each zone or layer bounded by a flooding surface. Each sand reservoir has particular characterization based on petrophysical properties that represent geological process. The petrophysical properties consist of shale volume, porosity, and water saturation obtained by wireline log calculation. This study uses conventional core data to validate the log calculation to achieve an accurate interpretation. Bekasap reservoir is a sandstone reservoir deposited in an estuarine with tide-dominated. Formation evaluation was done to determine the interest zone by petrophysical properties. The result well-log calculation and reservoir cut-offs showed the thickest reservoir in the BK 3 with the best average values of petrophysical properties with an average shale volume 0.32; porosity of 0.245. Otherwise, in rock type determination, four lithofacies are divided in the reservoir based on flow units. The sample RT 1 and RT2 provided the best reservoir zones with HFU1 and HFU2. The RT 3 and RT 4 dominated in HFU3 and HFU4 had the lowest potential zones of reservoir. The final findings showed a good correlation between sedimentologic analysis and petrophysical properties in the rock type determination. As a result, the best reservoir quality development is controlled by the depositional environment (texture and structure) rather than the diagenetic process in this reservoir. It is proven by petrophysical properties in BK1, and BK2 is coastal barrier sand (tidal sand bar) has more clean sand rather than in BK3 and BK4 deposited in the offshore bar.
Stability Analysis of Saka DAM Diversion Tunnel Portal Febrie Maulana Fajrin; Subagyo Pramumijoyo; I Gde Budi Indrawan
Journal of Applied Geology Vol 8, No 1 (2023)
Publisher : Geological Engineering Department Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jag.57578

Abstract

The Saka Dam has a channel in the form of a diversion tunnel. This paper presents the results of rock mass characterization using the Geological Strength Index (GSI) classification and evaluation of the stability of the tunnel portal slope with earthquake loads using numerical methods. Based on the GSI classification, the Saka Dam tunnel portal slope is composed of rock masses that are poor quality, fair, and good. The calculation results show the Saka Dam can experience earthquake loads with an acceleration value of 0.4g. Earthquake loads can cause a decrease in the safety value (SRF) of the tunnel portal slope based on the results of numerical analysis. SRF value of natural portal slope without earthquake effect is 10.23 (inlet) and 1.5 (outlet). SRF value of the design slope portal without earthquake effect is 6.64 (inlet) and 1.76 (outlet), whereas if the earthquake effect is taken into account the SRF value obtained is 20.31 (inlet) and 0.99 (outlet). This shows that the condition of the natural portal slope and the portal slope design planner section of the Saka Dam inlet diversion tunnel is in the safe category. Meanwhile, for the portal slope excavated from the outlet section, modification is needed to obtain a safe slope condition. The results of the modified geometry of the slopes at the outlet section resulted in an SRF value of 1.47 which indicates the slope is stable 
Identification of Permeable Structures and Heat Source in the Geothermal Working Area of Galunggung Volcano and the Heat Source Connectivity to the Karaha-Cakrabuana Area Using Gravity Data Leo Agung Prabowo; Salahuddin Husein; Sismanto Sismanto
Journal of Applied Geology Vol 8, No 1 (2023)
Publisher : Geological Engineering Department Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jag.60835

Abstract

Galunggung volcano area is a geothermal concession area that adjacent with Karaha-Cakrabuana concession area with a distance around 1 km. Indonesian Government planning to build power plant in 2025 so additional research needed to support the plan. Gravity survey could help in identifying permeable structure (fault) as well as heat source to a certain depth. The results of data processing showed the presence of faults seen on the FHD, SVD, and ABL residual maps, while for heat sources it was shown from the closed contour patterns on the ABL, residual, and regional maps. Derivative analysis in strengthens the position and type of fault from the match between the maximum FHD value and zero SVD value. From these results, identified the existence of three faults in the study area and were all identified as normal faults. 3D modelling gave a picture of density contrast in research area. From the section profile that pass through Galunggung and Telaga Bodas crater, heat source was interpreted as density with value 2.8 – 3.0 gr/cm3 and marked by orange to red color that coincide below Galunggung crater and continoued to Talaga Bodas crater at depths below -3000 masl. This indicate that both concession area was connected.
Determination of Overpressure Zone and Its Mechanism in Baong Formation of the "Y" Field in North Sumatera Basin Andrea Hasbullah; Hendra Amijaya; Jarot Setyowiyoto
Journal of Applied Geology Vol 8, No 1 (2023)
Publisher : Geological Engineering Department Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jag.63556

Abstract

The “Y” Field is one of the offshore areas in the North Sumatra Basin which is believed to have an important role in hydrocarbon exploration in the future. The North Sumatra Basin is known as an area that has high overpressure conditions and sometimes overpredicts in determining the amount of overpressure, especially in the Baong Formation. The purpose of this research is to determine the top and bottom overpressure zones, to know the vertical distribution of overpressure, and to find the main factors causing the overpressure in the Baong Formation.The data used in this study were 5 wells which have wireline log data, formation pressure data, leak of test, final well reports, mud logs, as well as 29 lines of 2D seismic data and 1 3D seismic data. The method used in this study was the Eaton method to determine pore pressure whereas the cross-plot wireline log method, the AI (acoustic impedance) inversion method and the stacking velocity were used to determine pore pressure.The study indicated that the overpressure zone is located in the Baong Formation at 1650 - 2108 m depth with a pore pressure of around 2891.70 - 3580 psi.  The overpressure is caused by loading mechanism, namely disequilibrium compaction. This is influenced by the thickness of the formation above Baong Formation.
Evaluation of Engineering Geological Conditions for Slope Stability Analysis of Diversion Tunnel Portal of Jlantah Dam, Karanganyar, Central Java Yayi Ismanda; I Gde Budi Indrawan; Heru Hendrayana
Journal of Applied Geology Vol 8, No 1 (2023)
Publisher : Geological Engineering Department Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jag.72438

Abstract

This paper presents the research results carried out to analyze the slope stability of the diversion tunnel portal of Jlantah Dam based on the quality of the rock mass. The classification of the rock mass quality at the tunnel location refers to the Geological Strength Index (GSI) method while the analysis of portal slope stability is modelled numerically with the element method using Phase2 software. The modelling of the tunnel portal slope design with and without earthquake load was carried out to obtain the safety factor (SF) value. The results showed that the study area consists of residual soil, andesite breccia and lapilli tuff rocks with rock mass quality based on the GSI value ranging from poor to fair. The inlet portal slope is composed of rocks that have poor and fair mass quality while the inlet section is composed of rocks that have poor mass quality. The SF value>1.3 for conditions without earthquake effect was achieved on slope design 1V:1.5H and SF value>1.1 for conditions with earthquake effect was achieved on slope design 1V:2H. The SRF value at the portal outlet location is greater than the SRF value at the portal inlet location for the same slope design conditions indicating that the rock mass quality at the portal outlet location is better than the rock mass quality at the portal inlet location.